Small Carcassonne game, never "the big one"

Mike ended up staying an extra night this weekend so we had a game of Carcassonne. However, as we were starting past 7:30, we used only a select number of add-on sets, less than usual. As it was, the game took until 11 and William was nearly asleep for his final few turns. Unless we plan around it and start in the afternoon, I doubt we'll ever put all the available tiles together to play the ultimate game we've talked about for the past year.